1. Field of the Invention
The present invention relates to a driving method for a flat panel display apparatus and the flat panel display apparatus for executing the driving method.
2. Description of the Prior Art
It is desired for mounting technique in the flat panel display apparatus to realize the high density mounting in order to expect simplification of the entire apparatus. Especially, high densification is required for mounting a driving IC (integrated circuit) for driving the display panel. FIG. 1 is a typical view of mounting method of a driving IC disclosed in, for example, Page 70 of "National Technical Report" (Feb. 1987), for satisfying the above requirement. This example forms an electrode pattern on a base film of polyimide resin and thermocompression-bonds a driving IC chip on the base film, thereby expecting an improvement in mounting density.
Referring to FIG. 1, reference numeral 1 designates a film carrier on which an electrode pattern is formed by plating Au on the surface layer of Ni. FIG. 2 is an enlarged view of the film carrier 1, at the center of which a driving IC chip 2 comprising a shift register and a level shifter is mounted, the driving IC chip 2 being rectangular when viewed in plane. FIG. 3 is typical view showing an arrangement of input and output terminals at the driving IC chip 2. Input signal terminals are arranged on one side of the rectangular chip 2, output signal terminals being arranged on other three sides counterclockwise (or clockwise) in regular order. The output signal lines from the output signal terminals at two parallel sides of the chip 2 show on the film carrier 1 a traveling pattern such that the output signal lines at first travel outwardly from the driving IC chip 2 and then perpendicularly bend and travel toward an electrode of a liquid crystal display panel 3.
The above-mentioned example using the film carrier 1 in order to mount the driving IC chip 2 improves the mounting density more than the IC packaged in the conventional way.
Next, explanation will be given on operation of the aforesaid conventional example.
The driving IC chip 2 is given display data sequentially through the input signal lines and outputs driving signals to the liquid crystal display panel 3 through the output signal lines. Concretely, the number of data, that is, the number of outputs, allotted to one driving IC chip 2 is represented by 2N, and the driving signals to be supplied to electrodes L (1), L(2) . . . L(2N) on the liquid crystal display panel 3 connected with the output signal lines of driving IC chip 2 are represented by S(1), S(2) . . . S(2N), S(1) being outputted from an output terminal OUT(1), S(2) from that OUT(2), and S(2N) from that OUT(2N), the display data corresponding to each driving signal are represented by D(1), D(2) . . . D(2N) and supplied in the order of D(1), D(2) . . . D(2N) to the driving IC chip 2".
Pitch between the picture elements on the liquid crystal display panel 3 becomes narrow following an improvement in resolution of the flat panel display apparatus, then the relation between a width w of the film carrier 1 and a product p.times.m of the pitch p between the picture elements multiplied by the number m of data allotted to one driving IC chip 2 becomes problematically. In case of the aforesaid conventional flat panel display apparatus width w of the film carrier 1 is limited by the sum of a width a of the driving IC chip 2 and pattern printing widths b and c. On the other hand, a width w.sub.R of film carrier 1 permitted for practical use depends on the product p.times.m.
As shown in FIG. 4, there is no problem when a relation of w.sub.R .gtoreq.w (p.times.m.gtoreq.a+b+c) is maintained, but when the pitch p between the picture elements decreases following the improvement in resolution of the liquid crystal display panel 3 to cause a relation of w.sub.R &lt;w (p.times.m&lt;a+b+c) as shown in FIG. 5, geometrical inconvenience, that is, the trouble-some problem about mounting between the adjacent film carriers 1 is caused.